Re: Lightning and multiple towers de N4KG
I recently added a seventh tower, 140 ft of Rohn 25 used as an
elevated GP on 160M, in the middle of 6 other towers. The towers
form an L running from north to south to east, ranging in height
from 40 ft (TH7), 60 ft (5L10 / 4L15 / 5L10), 80 ft (TH6 / TA32 /
140 ft (160M GP), 80 ft (3L20), 100 ft (2L40), and (east) 130 ft (3L15).
There are also 3 - 80M dipoles between towers. EVERY tower
sits in the ground around 30 inches or so with NO concrete. The
130 ft tower has the remains of 50 radials from a previous 160M
antenna. All transmission lines come down to the ground and are
returned to the house in shallow open trenches. There are NO
ground rods or other dissipating ground fields, but the tower legs
do provide approximately 3 square feet of surface area below ground.
(Yes, some of the older ones are showing signs of rust after 18 years.)
To the best of my knowledge, I have NEVER had a major strike
in the 18 years I have lived at this QTH, yet I have seen lightning
hit a field approximately 1/4 mile north of me while operating in
a DX contest (younger and more foolish days) and even strike
my next door neighbors power transformer, approximately 100 ft
WNW of my 40 ft tower. I HAVE had lightning damage come in on
the power lines. I have also seen evidence of a Beverage transformer's
wires vaporizing, presumably from induced currents as this particular
Beverage runs parallel to the power lines feeding my house for about
150 ft, spaced about 30 or 40 ft.
My land slopes to the east, dropping approximately 20 ft to a creek
that forms my eastern boundary where it flows through a woods.
The property is roughly 300 ft wide (E-W) by 540 ft deep (N-S).
de Tom N4KG
On Thu, 11 Jun 1998 15:41:01 -0400 (EDT) Bill Fisher - W4AN
>Does it make sense that a person with a lot of towers would stand less
>a chance of a strike than someone with just one tower? To me, it
>logical that 10 towers bleeding off energy would be better than just
>I ask because I have witnessed many T-storms at my station the past
>couple of years and have yet to see a hit on one of the towers. I
>seen MANY on the ridges around me.
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